bww3588

iTrader: (49)

The 5.3 I have came with the 585 coils, unfortunately, while the junk yard was pulling the engine they ruined 4 of the 8. I bought another set of 585's, but they got lost in the mail. The seller was nice enough to send me another set, but they are the regular, non heat sink truck coils. (12558693).

I know you have to change some things in the tune to swap from these, to 585's so I would assume the dwell needs to be changed as well to go back. Am I correct, or can I just bolt them on and go? I've already verified the connections are the same, although I need to use a different bracket.

bww3588

iTrader: (49)

Ttt...

Firebirdmuscle

iTrader: (16)

My tuner said I could swap them and go so I would assume you could too. Just guessing though.

bww3588

iTrader: (49)

I can't see it hurting anything. But Idk

Paul Bell

iTrader: (9)

I would suggest you stay with the D585 coils. Find another set.

They have the most output of all the coils.

If you change to the D581 coils, you'd also need to change the brackets.

themealonwheels

iTrader: (20)

Until my new brackets show up, I'm actually using stock 2000 fbody coils on my driver side and D585 coils on the passenger side. Now this may be a huge coincidence, but I triggered a couple of O2 sensor codes on the passenger side a few miles after installing the D585s. I cleared them and they came back. One is the bank running lean and the other I forgot... and it's a fairly new Denso O2 sensor, like less than 3k miles and 6 months.

I seriously don't think that the different coils on each side is the culprit, but I can't deny it until my new brackets get here. Food for thought...

thunderstruck507

iTrader: (18)

I would use the other truck coils if you already have them. The brackets will work and I never found any measurable gains with the d585 coils anyway.

1FastBrick

iTrader: (16)

In the past I have been told they were different.

However after comparing a stock file with square truck coils to another file with with round coils the timing and dwell were the same. The only difference I could see in the spark tables was in timing. The round coils had 1 additional degree across all the high and low octane tables.

bww3588

iTrader: (49)

If that's the case, I should be able to plug and go.

thunderstruck507

iTrader: (18)

I ran the square truck coils on a stock ls1 dwell table and later one copied from a truck with the square coils without noticing anything.

They fit the valve covers too you just have to bend the fuel rail entry a hair.